Bug fixes in hb script
Bug fixes in hb script

sh uses '.' to source a file. For some reason 'source' is allowed, but
not on all systems and therefore is not portable.

The '==' comparison is only for strings. The '-eq' comparison should be
used for numeric comparisons.

'exit' takes a value of 0-255. Use of a negative number, such as '-1',
is will throw an error.

Change-Id: Ib617f632a9c9ad11a28ad0e07154f364d8572f57
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/40579
Tested-by: Jenkins Server <8e3f934e4c44875bc48d33da3ea13d93ba9a233f@us.ibm.com>
Tested-by: Jenkins OP Build CI <e610bd72261d3c0a48f1e8ae36832ab00774d426@us.ibm.com>
Tested-by: FSP CI Jenkins <aa9e4d9ac7cd25905e9c0dd36d4150516e73dd86@us.ibm.com>
Reviewed-by: Elizabeth K. Liner <2cf7b278f097e7e2abe996aafb02aa8116b785d6@us.ibm.com>
Reviewed-by: Benjamin J. Weisenbeck <5c9571551d3c5d31d5a99a7e8d72fcb5684103ff@us.ibm.com>
Reviewed-by: Caleb N. Palmer <4dd1938fbd016e66315ec83516544b027a7e47e1@us.ibm.com>
Reviewed-by: Brian J. Stegmiller <4c05ea37f9d6efb9a2c94995009b8b66580a4c01@us.ibm.com>
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot